1. Field Of The Invention
The present invention relates to cutting apparatus and, more particularly, to a device having a stationary cutting means for severing predetermined-sized particles from a solid mass.
2. Description of Related Art
The device claimed does not seek to shred slivers of material from a larger mass nor grind, mill, crush or abrade such material. The object is to sever particles of a predetermined size from a given feedstock while minimizing harm to the cellular integrity of both the feedstock and the cut particles. This is important in the handling of some types of foodstuffs, chemicals and medical-related products and processes.
Especially in the field of bone grafting, cell vitality and bone regeneration are adversely affected by grinding, crushing or pulverizing processes. Thus, the invention provides a means to cut particles from pieces of bone with a shearing action that minimizes cellular damage.
Although entirely oblivious to the above purposes, U.S. Pat. No. 3,642,045 sets forth a cheese grater that is structurally related to the invention. It utilizes an open-ended outer casing with a grater plate supported by a shoulder about the lower inside of the casing. A second open-ended driver casing telescopes into the first casing. It has a partition secured to its opposing inner walls with a central pivot for extending through a central aperture in the grater plate. A third element called a pusher with a slotted bottom wall engages the partition when inserted into the driver casing. Rotation of the pusher causes rotation of the driver casing which moves chunks of cheese in the driver casing across the grater plate.
Some of the problems with the above are: 1) The partition cannot be removed from the drive casing for cleaning and sterilization. 2) There is no enclosure for receiving the grated particles. 3) When pushing materials against the grater plate, they will oftentimes move outwardly and become lodged in the spacing between the outer casing and driver casing. 4) The assembly requires a pivot shaft and cross pin to prevent the driver casing from being forced away from the grater by the peripheral accumulation of uncut material. 5) Because the driver casing and grater plate are pinned together, relative movement for cutting becomes impossible whenever the grater plate is dislodged, binds-up or becomes slightly elevated from the housing shoulder by accumulation of material under the plate. In fact, it is most often necessary to continuously force down the driver casing and attached plate against the housing shoulder by grasping the narrow upper ledge with one hand while rotating the pusher with the other hand.
Another prior art device using a cutter plate is shown in U.S. Pat. No. 953,790. In this patent the plate covers the open end of an enclosure and a vegetable in the enclosure is pushed against the plate as it rotates. The grated material is accumulated within the same enclosure. The openness of the enclosure, the vertical alignment of the plate, the radially aligned grater blades and the plate rotation make this device entirely dissimilar to the present invention.
In the field of bone grafting, live bone is comminuted for subsequent grafting purposes with auguring devices and rongeur assemblies. These devices, which are oftentimes powered, function to gnaw, nip, chew and pulverize the bone. When the devices are operated at high velocities, the bone becomes overheated. Also, the harsh mechanical processing results in a destruction of most of the bone cells. As such, most bone material subjected to the above become unusable for grafting purposes.